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    <title>ShellCheck: SC2270 – To assign positional parameters, use `set -- first second ..` (or use `[ ]` to compare).</title>
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    <h1>SC2270 – ShellCheck Wiki</h1>
    <a href="https://github.com/koalaman/shellcheck/wiki/SC2270">See this page on GitHub</a>
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    <h2
id="to-assign-positional-parameters-use-set----first-second--or-use---to-compare">To
assign positional parameters, use <code>set -- first second ..</code>
(or use <code>[ ]</code> to compare).</h2>
<h3 id="problematic-code">Problematic code:</h3>
<div class="sourceCode" id="cb1"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb1-1"><a href="SC2270.html#cb1-1" aria-hidden="true" tabindex="-1"></a><span class="cf">if</span> <span class="bu">[</span> <span class="ot">-z</span> <span class="st">&quot;</span><span class="va">$1</span><span class="st">&quot;</span> <span class="bu">]</span></span>
<span id="cb1-2"><a href="SC2270.html#cb1-2" aria-hidden="true" tabindex="-1"></a><span class="cf">then</span></span>
<span id="cb1-3"><a href="SC2270.html#cb1-3" aria-hidden="true" tabindex="-1"></a>  <span class="va">$1</span><span class="ex">=</span><span class="st">&quot;help&quot;</span></span>
<span id="cb1-4"><a href="SC2270.html#cb1-4" aria-hidden="true" tabindex="-1"></a><span class="cf">fi</span></span></code></pre></div>
<p>or</p>
<div class="sourceCode" id="cb2"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb2-1"><a href="SC2270.html#cb2-1" aria-hidden="true" tabindex="-1"></a><span class="cf">if</span> <span class="va">$1</span><span class="ex">=</span><span class="st">&quot;help&quot;</span></span>
<span id="cb2-2"><a href="SC2270.html#cb2-2" aria-hidden="true" tabindex="-1"></a><span class="cf">then</span></span>
<span id="cb2-3"><a href="SC2270.html#cb2-3" aria-hidden="true" tabindex="-1"></a>  <span class="bu">echo</span> <span class="st">&quot;Usage: </span><span class="va">$0</span><span class="st"> filename&quot;</span></span>
<span id="cb2-4"><a href="SC2270.html#cb2-4" aria-hidden="true" tabindex="-1"></a><span class="cf">fi</span></span></code></pre></div>
<h3 id="correct-code">Correct code:</h3>
<div class="sourceCode" id="cb3"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb3-1"><a href="SC2270.html#cb3-1" aria-hidden="true" tabindex="-1"></a><span class="cf">if</span> <span class="bu">[</span> <span class="ot">-z</span> <span class="st">&quot;</span><span class="va">$1</span><span class="st">&quot;</span> <span class="bu">]</span></span>
<span id="cb3-2"><a href="SC2270.html#cb3-2" aria-hidden="true" tabindex="-1"></a><span class="cf">then</span></span>
<span id="cb3-3"><a href="SC2270.html#cb3-3" aria-hidden="true" tabindex="-1"></a>  <span class="bu">set</span> <span class="at">--</span> <span class="st">&quot;help&quot;</span></span>
<span id="cb3-4"><a href="SC2270.html#cb3-4" aria-hidden="true" tabindex="-1"></a><span class="cf">fi</span></span></code></pre></div>
<p>or</p>
<div class="sourceCode" id="cb4"><pre class="sourceCode sh"><code class="sourceCode bash"><span id="cb4-1"><a href="SC2270.html#cb4-1" aria-hidden="true" tabindex="-1"></a><span class="cf">if</span> <span class="bu">[</span> <span class="va">$1</span> <span class="ot">=</span> <span class="st">&quot;help&quot;</span> <span class="bu">]</span></span>
<span id="cb4-2"><a href="SC2270.html#cb4-2" aria-hidden="true" tabindex="-1"></a><span class="cf">then</span></span>
<span id="cb4-3"><a href="SC2270.html#cb4-3" aria-hidden="true" tabindex="-1"></a>  <span class="bu">echo</span> <span class="st">&quot;Usage: </span><span class="va">$0</span><span class="st"> filename&quot;</span></span>
<span id="cb4-4"><a href="SC2270.html#cb4-4" aria-hidden="true" tabindex="-1"></a><span class="cf">fi</span></span></code></pre></div>
<h3 id="rationale">Rationale:</h3>
<p>You have a command on the form <code>$2=value</code>.</p>
<p>If the goal is to assign a new value to the positional parameters,
use the <code>set</code> builtin: <code>set -- one two ..</code> will
cause <code>$1</code> to be "one" and <code>$2</code> to be "two".</p>
<p>If you instead want to compare the value, use <code>[ ]</code> and
add spaces: <code>[ "$1" = "foo" ]</code></p>
<h3 id="exceptions">Exceptions:</h3>
<p>None</p>
<h3 id="related-resources">Related resources:</h3>
<ul>
<li>Help by adding links to BashFAQ, StackOverflow, man pages, POSIX,
etc!</li>
</ul>
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